- Clinical history of chronic obstructive pulmonary disease and a confirmatory diagnosis based on pulmonary function tests performed at the Outpatient Screening Visit, with moderate to severe airflow limitation defined by: Moderate: forced expiratory volume in one second to forced vital capacity less than 70%; 50% less than forced expiratory volume in one second; less than 80% predicted. Severe: forced expiratory volume in one second to forced vital capacity less than 70%; forced expiratory volume in one second less than 50% predicted.